920
FXUS65 KBYZ 131236
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
636 AM MDT MON JUL 13 2026
KEY MESSAGES
- SOMEWHAT COOLER, BUT STILL HOT TO START THE WORK WEEK. EXTREME
HEAT WARNING EXTENDED FOR PORTIONS OF SOUTHERN MT AND NORTHERN
WY THROUGH TUESDAY...AND FAR SOUTHEAST MT INTO WEDNESDAY.
- MONSOONAL MOISTURE INCREASES BY MIDWEEK BRINGING A CHANCE OF
THUNDERSTORMS TO THE REGION.
UPDATE
SATELLITE IMAGERY SHOWS CLEAR SKIES ACROSS THE AREA IN THE WAKE OF
LAST NIGHT'S WEAK COLD FRONTAL PASSAGE. THIS FRONT HAS ACTUALLY
NOT REACHED THE DAKOTAS BORDER YET, AND WON'T UNTIL THIS EVENING
AS IT IS STALLING. INTERESTINGLY, THE FRONT HAS TAPPED INTO MOIST
AIR TO OUR NORTH. THE DEW POINT AT MILES CITY IS UP TO 58F AND
FURTHER NORTH SOME SITES ARE IN THE LOWER 60S. TO OUR SW, MONSOON
MOISTURE IS ADVECTING RAPIDLY NORTHWARD. BLENDED TPW IMAGERY SHOWS
VALUES NEAR AN INCH IN SOUTHWEST ID AS WELL AS ALONG THE CANADIAN
BORDER. VERY INTERESTING EVOLUTION THAT WILL NEED TO BE MONITORED
TODAY. EXPECTATION IS STILL FOR ISOLATED T-STORMS IN OUR WEST
BEGINNING AROUND 21Z. THESE WILL BE HIGH-BASED AND MAY PRODUCE
GUSTY WINDS (GREATEST CHANCE OF THIS IN CENTRAL MT PER THE DAY1
OUTLOOK FROM SPC), BUT AS PWATS CLIMB RAPIDLY THEY MAY NOT BE AS
DRY AS INITIALLY THOUGHT. TODAY WILL BE HOT WITH TEMPS IN THE MID
90S WEST TO NEAR 105F EAST. DESPITE THE HEAT, VERY WARM MID LEVELS
AND EASTERLY SURFACE WINDS WILL RESULT IN CAPPING ACROSS LOWER
ELEVATIONS. AGAIN THIS IS SOMETHING TO WATCH, ESPECIALLY ONCE
CONVECTION BEGINS TO DEVELOP OVER THE MOUNTAINS THIS AFTERNOON.
STAY SAFE FROM THE HEAT, FOLKS. JKL
DISCUSSION
NEXT 7 DAYS (THROUGH SUNDAY)...
A COLD FRONT IS DROPPING THROUGH THE AREA FROM THE NORTHWEST,
BRINGING A WIND SHIFT AND A GRADUAL INCREASE IN RELATIVE
HUMIDITY. WARM TEMPERATURES WILL CONTINUE OVERNIGHT, WITH BREEZY
SOUTHERLY WINDS AHEAD OF THE COLD FRONT, ESPECIALLY OVER THE
SOUTHEAST WHERE A LOW LEVEL JET IS IN PLACE. EXPECT THE FRONT TO
MOVE THROUGH THE FAR SOUTHEAST THIS MORNING AFTER SUNRISE.
TEMPERATURES WILL BE ABOUT 5 TO 15 DEGREES COOLER TODAY, RELATIVE
TO YESTERDAY, BUT HIGHS WILL STILL BE IN THE UPPER 90S TO AROUND
100 DEGREES, WARMEST OVER THE EAST.
WHILE TEMPERATURES TREND A LITTLE COOLER HEADING INTO MID WEEK AS
THE RIDGE AXIS SHIFTS EAST, THE EASTERN AREAS WILL CONTINUE TO SEE
HOT TEMPERATURES. VERY WARM OVERNIGHT LOWS AND HIGH TEMPERATURES
INTO THE 100 TO 105 DEGREE RANGE CONTINUE IN FAR EASTERN MONTANA
AND SHERIDAN COUNTY, WY INTO WEDNESDAY. THE EXTREME HEAT WARNING
CONTINUES TODAY FOR ALL AREAS, CONTINUING FOR PORTIONS OF THE EAST
ON TUESDAY AND WEDNESDAY DUE TO THE PROLONGED HOT DAYTIME
TEMPERATURES AND WARM OVERNIGHT LOWS.
OTHERWISE, HIGHS IN THE LOWER TO MID 90S WILL BE COMMON THROUGH
THE REMAINDER OF THE WEEK INTO THE UPCOMING WEEKEND. MODELS
CONTINUE TO INDICATE MONSOONAL MOISTURE WILL SLIDE INTO OUR REGION
FROM THE SOUTHWEST WITH HINTS OF OCCASIONAL WEAK IMPULSES IN THE
MEAN FLOW. AT A MINIMUM, THIS LOOKS TO BRING AN INCREASE IN
RELATIVE HUMIDITY, WITH A MODERATE CHANCE OF DAILY
SHOWERS/THUNDERSTORMS FOR THE AREA, GREATEST OVER WESTERN AREAS.
ENSEMBLES CONTINUE TO PROG HIGH PWATS, REACHING UP TO 1.50 INCHES
IN THE AREA FROM TUESDAY ONWARD. SO ANY DECENT IMPULSE IN THE
MONSOONAL FLOW MAY RESULT IN STORMS WITH LOCALLY HEAVY RAINFALL.
FIRE WEATHER...ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS WILL
LINGER IN OUR EAST INTO THE EARLY MORNING HOURS (ESPECIALLY ALONG
RIDGES) DUE TO A LOW LEVEL JET AND SLOW RH RECOVERY AS THE WEAK
FRONT SLIDES OVER THE AREA. TAKE CARE NOT TO CAUSE A SPARK.
STP
AVIATION
AN EARLY MORNING WEAK COLD FRONT HAS PUSHED THROUGH KMLS & KSHR
AND WILL STALL BEFORE REACHING THE DAKOTAS BORDER. WEST OF THE
FRONT, WINDS WILL SHIFT TO THE N-NE-E WITH 15-25KT GUSTS. BY LATE
AFTERNOON & EVENING, ISOLATED HIGH-BASED T-STORMS ARE EXPECTED IN
THE WEST, POSSIBLY IMPACTING KLVM-K6S0-KHWQ (BUT LOW CONFIDENCE AT
THIS TIME SO HAVE NOT INCLUDED TS IN THE KLVM TAF). STORMS COULD
PRODUCE ERRATIC WIND GUSTS OF 30-50KTS. THIS WILL BE SOMETHING TO
WATCH THROUGH THE DAY. OTHERWISE, VFR WILL PREVAIL THROUGH THE
PERIOD. JKL
PRELIMINARY POINT TEMP/POPS
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 098 069/100 071/094 066/092 066/095 067/094 066/092
0/U 00/U 34/T 63/T 40/U 21/U 21/U
LVM 096 058/096 061/091 057/090 058/094 059/092 059/091
1/U 12/T 48/T 75/T 42/T 22/T 32/T
HDN 100 068/102 069/097 065/094 065/096 066/095 064/093
0/U 00/G 21/U 53/T 41/B 21/U 21/U
MLS 101 070/104 073/101 069/095 068/097 068/096 067/093
0/N 00/G 10/G 11/B 21/B 21/U 11/U
4BQ 101 068/104 074/101 070/094 068/096 069/094 067/092
0/G 00/G 00/G 11/U 21/B 21/U 21/U
BHK 104 066/103 070/102 067/094 063/095 063/094 062/091
0/G 00/G 00/G 00/U 21/U 21/U 11/U
SHR 099 059/102 065/097 062/092 061/094 062/093 061/091
0/U 00/G 01/U 35/T 42/T 13/T 23/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...EXTREME HEAT WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR
ZONES 29-34-40-42-56-63>66-141-170-172-228.
EXTREME HEAT WARNING IN EFFECT UNTIL MIDNIGHT MDT TUESDAY
NIGHT FOR ZONES 30-31-57-138-139-169-173-235.
EXTREME HEAT WARNING IN EFFECT UNTIL MIDNIGHT MDT WEDNESDAY
NIGHT FOR ZONES 32-33-36-37-58.
WY...EXTREME HEAT WARNING IN EFFECT UNTIL MIDNIGHT MDT WEDNESDAY
NIGHT FOR ZONE 199.
WEATHER.GOV/BILLINGS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page